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Home >> Mazda >> 2021 >> CX-9 Signature >> Repair and Diagnosis >> Engine Performance >> System >> On-Board Diagnostic - Engine Control System (4 Of 6) >> DTC P0628-00: Fuel Pump Control Module Circuit Low Input >> Diagnostic Procedure
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Diagnostic Procedure

DTC P0628:00 DIAGNOSTIC PROCEDURE

STEP INSPECTION ACTION
1 RECORD VEHICLE STATUS AT TIME OF DTC DETECTION TO UTILIZE WITH REPEATABILITY VERIFICATION
NOTE:
  • Recording can be facilitated using the screen capture function of the PC.
  • Record the snapshot data on the repair order.
 - Go to the next step.
2 VERIFY RELATED REPAIR INFORMATION AVAILABILITY
  • Verify related Service Bulletins and/or on-line repair information availability.
  • Is any related repair information available?
 Yes Perform repair or diagnosis according to the available repair information.
  • If the vehicle is not repaired, go to the next step.
No Go to the next step.
3 INSPECT FUEL PUMP UNIT CONNECTOR CONDITION
  • Switch the ignition off.
  • Disconnect the fuel pump unit connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 9.
No Go to the next step.
4 INSPECT FUEL PUMP UNIT
 Yes Replace the fuel pump unit, then go to Step 9.
(See FUEL PUMP UNIT REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
5 INSPECT FUEL PUMP CONTROL MODULE CONNECTOR CONDITION
  • Disconnect the fuel pump control module connector.
  • Inspect for poor connection (such as damaged/pulled-out pins, corrosion).
  • Is there any malfunction?
 Yes Repair or replace the connector and/or terminals, then go to Step 9.
No Go to the next step.
6 INSPECT FUEL PUMP UNIT CONTROL CIRCUIT FOR SHORT TO GROUND
  • Verify that the fuel pump unit and fuel pump control module connectors are disconnected.
  • Inspect for continuity between fuel pump unit terminal A (wiring harness-side) and body ground.
  • Is there continuity?
 Yes Refer to appropriate wiring diagram and verify whether or not there is a common connector between fuel pump unit terminal A and fuel pump control module terminal 2C.
If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for a short to ground.
  • Repair or replace the malfunctioning part.

If there is no common connector:
  • Repair or replace the wiring harness which has a short to ground.

Go to Step 9.
No Go to the next step.
7 INSPECT FUEL PUMP UNIT CIRCUIT FOR OPEN CIRCUIT
  • Verify that the fuel pump unit and fuel pump control module connectors are disconnected.
  • Inspect for continuity between the following terminals (wiring harness-side):
    • Fuel pump unit terminal A-Fuel pump control module terminal 2C
      • Fuel pump unit terminal B-Fuel pump control module terminal 2D
  • Is there continuity?
 Yes Go to the next step.
No Refer to appropriate wiring diagram and verify whether or not there is a common connector between the following terminals:
  • Fuel pump unit terminal A-Fuel pump control module terminal 2C
  • Fuel pump unit terminal B-Fuel pump control module terminal 2D

If there is a common connector:
  • Determine the malfunctioning part by inspecting the common connector and the terminal for corrosion, damage, or pin disconnection, and the common wiring harness for an open circuit.
  • Repair or replace the malfunctioning part.

If there is no common connector:
  • Repair or replace the wiring harness which has an open circuit.

Go to Step 9.
8 INSPECT FUEL PUMP CONTROL MODULE
 Yes Replace the fuel pump control module, then go to the next step.
(See FUEL PUMP CONTROL MODULE REMOVAL/INSTALLATION [SKYACTIV-G 2.5T] .)
No Go to the next step.
9 VERIFY DTC TROUBLESHOOTING COMPLETED
 Yes Repeat the inspection from Step 1.

Go to the next step.
No Go to the next step.
10 VERIFY AFTER REPAIR PROCEDURE
 Yes Go to the applicable DTC inspection.
(See DTC TABLE [PCM (SKYACTIV-G 2.5T)] .)
No DTC troubleshooting completed.
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